Uber is controversial, but one thing everyone seems to agree on is that the ride-sharing service takes drunken drivers off the roads. This isn’t just the ride-sharing service blowing smoke. While Uber has shared anecdotal evidence and its own study showing a decline in DUI arrests because of Uber, two Temple University professors added legitimacy to the company’s claims last year by finding alcohol-related car crashes dropped by as much as 5.6 percent in California cities following the entrance of UberX.

The thought is UberX offers choice. Partiers who might consider driving home in the pre-ride-sharing days now have an easily accessible and generally affordable alternative.

In 2015, after a late October 2014 launch of UberX, Philadelphia experienced its first full year of the service.

And instead of going down, drunken driving numbers went… up. Way up.

DUI arrests and alcohol-related fatal crashes increased in 2015 compared to the previous year. The alcohol-related fatal crashes were at their second-highest level in the last five years.

These numbers differ from the rest of Pennsylvania, which saw a 2 percent decrease in DUI arrests from 2014 to 2015, as well as a 2 percent drop in alcohol-related fatal crashes. Allegheny County, the second largest county in Pennsylvania behind Philadelphia, saw its DUI arrests plummet 18 percent from 2014 to 2015.

Alcohol-related fatal crashes in Allegheny County fell an even steeper amount in its first full year of having UberX: from 19 to 9, a decrease of more than 100 percent. Philly’s went up about 30 percent.

“That’s striking,” says Brad Greenwood, one of the Temple professors who completed the Uber study last year. “The mind reels.”

The study by Greenwood and professor Sunnil Wattal looked at small and large cities in California from 2009 to 2014 and examined numerous variables for every accident to reduce the possibility of other factors contributing to possible dropoffs. They ended up finding UberX, the most common and least expensive service offered by Uber, led to a dropoff in alcohol-related car crashes of 3.6 percent to 5.6 percent. If the results were replicated throughout the country, the authors posited Uber could save 500 lives a year.

The biggest decreases in alcohol-related fatal crashes happened in the biggest cities. So conceivably Philadelphia should be seeing the dropoff. The study noted the dropoff effects usually didn’t take hold until UberX had been available for about nine-to-15 months. During the second half of 2015, as Philadelphia was reaching the nine-to-15 month range since the launch of UberX, more alcohol-related fatalities occurred, 19, than in the first half of 2015, 10.

A spokesperson for Uber gave the following statement after being briefed on the data from Philadelphia and surrounding areas: “It is somewhat early to determine what impact ridesharing can have on drunk driving in Philadelphia. We do know through our work with Mothers Against Drunk Driving and through independent studies that when people have affordable, reliable options like Uber, they’re able to make smarter choices.”

Greenwood called the suburban changes in alcohol-related fatal crashes a reasonable downward trend. He said he would have to study Philadelphia specifically to find why it’s seeing results different from the California study, as well as Allegheny and other neighboring counties, but a number of a reasons could be at play. One possibility that comes to mind is the PPA’s continued crusade against UberX. Unlike the rest of Pennsylvania, UberX is technically not legal in Philly.

Despite this barrier, Uber still gained widespread popularity in 2015. The service featured 12,000 drivers as of its one-year anniversary last October, and 700,000 individuals had taken an Uber in Philadelphia. The number of drivers ranks among the highest number in the country but behind similar cities like Los Angeles, Washington DC and Chicago.

Greenwood wondered whether the PPA’s testy relationship with Uber was causing fewer people to become drivers. A smaller number of drivers means higher surge pricing. And according to the Temple study, surge pricing means little to no effect on alcohol-related car accidents.

Then again, Philadelphia might just be an anomaly. Greenwood said any number of variables could have prevented an UberX-related dropoff from happening here. Nightlife, for instance, could just be getting wilder, leading more people to drink in Philadelphia.

Or perhaps the UberX effects seen in California won’t be replicated elsewhere around the country. Greenwood and Wattal are working on a bigger study that could offer more insight.